About the Authors

Chunfang Qiu

Chun-fang.Qiu@Swedish.org

Affiliation Center for Perinatal Studies, Swedish Medical Center, Seattle, Washington, United States of America

Karin Hevner

Affiliation Center for Perinatal Studies, Swedish Medical Center, Seattle, Washington, United States of America

Daniel A. Enquobahrie

Affiliations Center for Perinatal Studies, Swedish Medical Center, Seattle, Washington, United States of America, Department of Epidemiology, University of Washington School of Public Health, Seattle, Washington, United States of America

Michelle A. Williams

Affiliations Center for Perinatal Studies, Swedish Medical Center, Seattle, Washington, United States of America, Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: CFQ MAW. Performed the experiments: KH. Analyzed the data: CFQ MAW. Contributed reagents/materials/analysis tools: MAW KH. Wrote the paper: CFQ KH DAE MAW.